Distillative freezing process for separating volatile mixtures and apparatuses for use therein

摘要

The distillative freezing process disclosed is useful in separating and purifying a mixture that contains a volatile and crystallizing component and one or more volatile and non-crystallizing components by vaporizing the volatile components from the mixture under a sufficiently reduced pressure to thereby simultaneously form a mass of solid enriched with the crystallizing component. Two components of a mixture processed are denoted as the key components: one is the crystallizing component and is denoted as B-component; the other is the non-crystallizing component present in the greatest amount and is denoted as A-component. For a mixture to be processable by the process, it is necessary that the vapor pressure ratio of the key components be within a certain range and a low pressure phase diagram of the binary system of the key components belongs to certain types of phase diagrams.